Methods for forming connnectorized fiber optic cabling

ABSTRACT

A connectorized fiber optic cabling assembly includes a loose tube fiber optic cable and a connector assembly. The cable has a termination end and includes: an optical fiber bundle including a plurality of optical fibers; at least one strength member; and a jacket surrounding the optical fiber bundle and the at least one strength member. The connector assembly includes a rigid portion and defines a fiber passage. The connector assembly is mounted on the termination end of the cable such that the optical fiber bundle extends through at least a portion of the fiber passage. The plurality of optical fibers of the optical fiber bundle have a ribbonized configuration in the rigid portion of the connector assembly and a loose, non-ribbonized configuration outside the rigid portion. The plurality of optical fibers undergo a transition from the ribbonized configuration to the loose, non-ribbonized configuration in the rigid portion of the connector assembly. According to some embodiments, the rigid portion of the connector assembly includes a rigid connector housing.

CLAIM OF PRIORITY

This application claims priority under 35 U.S.C. §120 as a continuationof U.S. patent application Ser. No. 12/818,586, filed Jun. 18, 2010,which is a continuation-in-part application of U.S. patent applicationSer. No. 12/423,435, filed Apr. 14, 2009, now U.S. Pat. No. 7,758,257,which in turn is a continuation of U.S. patent application Ser. No.11/438,647, filed May 22, 2006, now U.S. Pat. No. 7,537,393, which inturn claims the benefit of priority from U.S. Provisional PatentApplication No. 60/688,492, filed Jun. 8, 2005, and U.S. ProvisionalPatent Application No. 60/688,493, filed Jun. 8, 2005. The disclosuresof each of the above applications are incorporated herein by referencein their entireties.

FIELD OF THE INVENTION

The present invention relates to communications cabling and, moreparticularly, to connectorized fiber optic cabling and methods forforming the same.

BACKGROUND OF THE INVENTION

Fiber array connectors are commonly employed to terminate multi-fiberfiber optic cables. Such connectors require that the fibers of the cablebe arranged in a row or side-by-side, aligned configuration. In somecases, multiple, stacked layers or rows of fibers may be used. Onemethod for providing fibers so arranged is to use ribbonized cabling.However, ribbonized cabling may suffer from drawbacks in bendability andcost. Another method is to use loose tube fiber cabling, ribbonize arelatively long section (e.g., from about 2 to 8 inches) of the fibersand install furcation tubing and other components on the cabling. Thismethod using furcation tubing may suffer from various drawbacks in cost,bendability, installation requirements, etc. For example, epoxytypically must be used to secure a transition between the cable and thefurcation tubing.

SUMMARY OF THE INVENTION

According to embodiments of the present invention, a connectorized fiberoptic cabling assembly includes a loose tube fiber optic cable and aconnector assembly. The cable has a termination end and includes: anoptical fiber bundle including a plurality of optical fibers; at leastone strength member; and a jacket surrounding the optical fiber bundleand the at least one strength member. The connector assembly includes arigid portion and defines at least one fiber passage. The connectorassembly is mounted on the termination end of the cable such that theoptical fiber bundle extends through at least a portion of the at leastone fiber passage. The plurality of optical fibers of the optical fiberbundle have a ribbonized configuration in the rigid portion of theconnector assembly and a loose, non-ribbonized configuration outside therigid portion. The plurality of optical fibers undergo a transition fromthe ribbonized configuration to the loose, non-ribbonized configurationin the rigid portion of the connector assembly. According to someembodiments, the rigid portion of the connector assembly includes arigid connector housing.

According to method embodiments of the present invention, a method forforming a connectorized fiber optic cabling assembly includes providinga loose tube fiber optic cable having a termination end and including:an optical fiber bundle including a plurality of optical fibers having aloose, non-ribbonized configuration; at least one strength member; and ajacket surrounding the optical fiber bundle and the at least onestrength member. The method further includes mounting a connectorassembly including a rigid portion and defining at least one fiberpassage on the termination end of the cable such that the optical fiberbundle extends through at least a portion of the at least one fiberpassage, and such that the plurality of optical fibers of the opticalfiber bundle have a ribbonized configuration in the rigid portion of theconnector assembly and a loose, non-ribbonized configuration outside therigid portion, and the plurality of optical fibers undergo a transitionfrom the ribbonized configuration to the loose, non-ribbonizedconfiguration in the rigid portion of the connector assembly. Accordingto some embodiments, the rigid portion of the connector assemblyincludes a rigid connector housing.

According to some embodiments, a connectorized fiber optic cablingassembly includes a loose tube fiber optic cable and a connectorassembly. The loose tube fiber optic cable has a termination end andincludes: an optical fiber bundle including a plurality of opticalfibers; at least one strength member; and a jacket surrounding theoptical fiber bundle and the at least one strength member. The connectorassembly is mounted directly on the termination end of the cable. Theplurality of optical fibers of the optical fiber bundle have aribbonized configuration in the connector assembly and a loose,non-ribbonized configuration outside the connector assembly and in thecable. According to some embodiments, the cable is a round, loose tubecable.

According to some embodiments, a method for forming a connectorizedfiber optic cabling assembly includes providing a loose tube fiber opticcable having a termination end and including: an optical fiber bundleincluding a plurality of optical fibers; at least one strength member;and a jacket surrounding the optical fiber bundle and the at least onestrength member. The method further includes mounting a connectorassembly directly on the termination end of the cable such that theplurality of optical fibers of the optical fiber bundle have aribbonized configuration in the connector assembly and a loose,non-ribbonized configuration outside the connector assembly and in thecable. According to some embodiments, the cable is a round, loose tubecable.

Further features, advantages and details of the present invention willbe appreciated by those of ordinary skill in the art from a reading ofthe figures and the detailed description of the preferred embodimentsthat follow, such description being merely illustrative of the presentinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front perspective view of a connectorized cabling inaccordance with embodiments of the present invention.

FIG. 2 is a front exploded, perspective view of the connectorizedcabling of FIG. 1.

FIG. 3 is a rear exploded, perspective view of the connectorized cablingof FIG. 1.

FIG. 4 is a cross-sectional view of the connectorized cabling of FIG. 1taken along the line 4-4 of FIG. 1.

FIG. 5 is a cross-sectional view of the connectorized cabling of FIG. 1taken along the line 5-5 of FIG. 1.

FIG. 6 is an enlarged, fragmentary view of a cable forming a part of theconnectorized cabling of FIG. 1.

FIG. 7 is a cross-sectional view of an optical fiber forming a part ofthe cable of FIG. 6.

FIGS. 8-13 illustrate method steps for forming the connectorized cablingof FIG. 1 in accordance with method embodiments of the presentinvention.

FIG. 14 is a fragmentary, perspective view of a cordage in accordancewith embodiments of the present invention.

FIGS. 15-17 illustrate method steps for forming a connectorized cable inaccordance with further embodiments of the present invention

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

The present invention now will be described more fully hereinafter withreference to the accompanying drawings, in which illustrativeembodiments of the invention are shown. In the drawings, the relativesizes of regions or features may be exaggerated for clarity. Thisinvention may, however, be embodied in many different forms and shouldnot be construed as limited to the embodiments set forth herein; rather,these embodiments are provided so that this disclosure will be thoroughand complete, and will fully convey the scope of the invention to thoseskilled in the art.

It will be understood that when an element is referred to as being“coupled” or “connected” to another element, it can be directly coupledor connected to the other element or intervening elements may also bepresent. In contrast, when an element is referred to as being “directlycoupled” or “directly connected” to another element, there are nointervening elements present.

In addition, spatially relative terms, such as “under”, “below”,“lower”, “over”, “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. It will beunderstood that the spatially relative terms are intended to encompassdifferent orientations of the device in use or operation in addition tothe orientation depicted in the figures. For example, if the device inthe figures is inverted, elements described as “under” or “beneath”other elements or features would then be oriented “over” the otherelements or features. Thus, the exemplary term “under” can encompassboth an orientation of over and under. The device may be otherwiseoriented (rotated 90 degrees or at other orientations) and the spatiallyrelative descriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof. Like numbers refer to like elementsthroughout. As used herein the term “and/or” includes any and allcombinations of one or more of the associated listed items.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this invention belongs. It will befurther understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

With reference to FIGS. 1-5, a connectorized cabling or cordage assembly10 according to embodiments of the present invention is shown therein.The connectorized cabling 10 includes a cable 20 and a connectorassembly 100. The connector assembly 100 may be an optical fiber arrayor multi-fiber push-on (MPO) type connector (which may also be referredto as an oval connector). The connector assembly 100 may be a plugconnector as shown or, alternatively, a female jack connector withsuitable modifications.

The cable 20 may be a breakout or subunit cable from a larger cableincluding multiple cable subunits and one or more additional jackets.According to some embodiments, the cable 20 is constructed as disclosedin co-assigned U.S. patent application Ser. No. 11/412,616, filed Apr.27, 2006, entitled Fiber Optic Cables and Methods for Forming the Same,the disclosure of which is incorporated herein by reference.

As shown in FIG. 6, the cable 20 includes generally a plurality ofnon-buffered optical fibers 42 (collectively forming a fiber bundle 40),a plurality of strength members or yarns 52 (collectively forming a yarnbundle 50), and a protective jacket 60. According to some embodimentsand as illustrated, the cable 20 is round in cross-section and theforegoing groups of components are substantially concentricallypositioned about and extend together along a length axis L-L. Accordingto some embodiments, the fiber bundle 40 includes at least eight (8)non-buffered optical fibers 42. As shown, the fiber bundle 40 includestwelve (12) non-buffered optical fibers 42. According to someembodiments, the optical fibers 110 are loose with respect to oneanother so that they have no particular, fixed relative orientation.

An exemplary one of the optical fibers 42 is shown in cross-section inFIG. 7. The optical fiber 42 includes a glass fiber 43, which includes aglass core 43A and a surrounding glass cladding 43B. The glass fiber 43may be constructed in any suitable manner. For example, each of the core43A and the cladding 43B may include one or more concentric segments orlayers, may be doped, etc. The glass fiber 43 may be formed of anysuitable materials and using any suitable methods. A coating layer 44surrounds the cladding 43B. The coating layer 44 provides environmentalprotection for the glass fiber 43. As illustrated, the coating layer 44consists of a single coating layer; however, multiple concentric layersmay be applied to form the overall layer 44. According to someembodiments, the coating layer 44 is formed of a UV light-curedacrylate. The coating layers 44 of the respective optical fibers 42 mayhave different colors for color-coding purposes.

According to some embodiments and as illustrated, the optical fiber 42is an optical fiber constructed as commonly referred to as a “bareoptical fiber” or a “non-buffered optical fiber”. According to someembodiments, the overall diameter D1 of the optical fiber 42 is in therange of from about 235 to 265 μm. According to some embodiments, thethickness T1 of the coating layer 44 is no greater than about 70.5 μm.According to some embodiments, the overall diameter D1 is between about235 to 265 μm and the thickness T1 of the coating layer 44 is no greaterthan about 70.5 μm. According to some embodiments, the diameter D2 ofthe core 43A is between about 6 and 64 μm and the diameter D3 of thecladding 43B is between about 115 and 135 μm.

As shown, the bundle 50 of the strength yarns 52 at least partiallysurrounds the optical fiber bundle 40. The strength yarns 52 may beformed of any suitable material. According to some embodiments, thestrength yarns 52 are aramid fibers. Other suitable materials mayinclude fiberglass or polyester. According to some embodiments, thestrength yarns 52 each have a denier in the range of from about 250 to3000. According to some embodiments, the strength yarn bundle 50includes between about 2 and 10 ends or strands of the strength yarns 52(which may each include hundreds of filaments).

The jacket 60 surrounds the yarn bundle 50 and the optical fiber bundle40, which reside in a longitudinal passage defined in the jacket 60. Thejacket 60 may be formed of any suitable material such as a polymericmaterial. According to some embodiments, the jacket 60 is formed of athermoplastic polymer. According to some embodiments, the thickness ofthe jacket 60 is between about 0.20 and 1.0 mm. According to someembodiments, the outer diameter D4 (FIG. 6) of the jacket 60 (i.e., theouter diameter of the cable 20) is between about 2.75 and 3.25 mm andthe cable 20 may be generally regarded as a 3.0 mm cable.

According to some embodiments, the inner diameter of the jacket passageis greater than the combined cross-sectional diameter of the opticalfiber bundle 40 and the strength yarn bundle 50 so that at least theoptical fibers 42 are loose and able to float within the jacket passage(i.e., move freely with respect to the jacket 60). According to someembodiments, both the optical fibers 42 and the strength yarns 52 areloose and can float within the jacket passage (i.e., can move freelywith respect to the jacket 60). Thus, at least a portion of the volumeof the jacket passage is not filled by the optical fibers 42 or thestrength yarns 52 to allow movement of the optical fibers 42 and thestrength yarns 52 within the jacket passage. The cable 20 may bereferred to as a “round, loose tube cable”. According to someembodiments, a non-round (e.g., oval) loose tube fiber optic cable canbe employed instead.

The connector assembly 100 includes a connector housing 105, a ferrule120, epoxy 128 (FIGS. 4 and 5), a ferrule boot 130, ferrule pins 132, apin retainer 134, a spring 136, a crimp sleeve 150, and a strain reliefboot 160. The connector housing 105 includes a front housing 110 and arear housing 140. These components will be discussed in more detailbelow.

The front housing 110 includes an inner part 112 and an outer part 114that are relatively slidable. A passage 116 extends through the fronthousing 110. The passage 116 has a generally oval or rectangular lateralcross-section.

The front housing 110 is substantially rigid. The front housing 110 maybe formed of any suitable material. According to some embodiments, thefront housing 110 is formed of a thermoplastic. According to someembodiments, the front housing 110 is formed of a polymeric materialsuch as polyethermide. According to some embodiments, the front housing110 has a flexural modulus of at least about 2 GPa. The front housing110 may be formed using any suitable method such as molding.

The ferrule 120 defines a cavity 122 and a rear opening 124A and a topopening 124B each communicating with the cavity 122. Fiber holes 124Cand pin holes 124D extend longitudinally through the ferrule 120. Thefiber holes 124C are configured in side-by-side alignment across thewidth of the ferrule 120. The ferrule 120 has a front face 126. Theferrule 120 may be formed using any suitable materials and techniques.According to some embodiments, the ferrule 120 is formed of a polymericmaterial and, according to some embodiments, a composite material suchas a glass filled polymer.

The ferrule boot 130 is tubular and may be formed of rubber. The ferrulepins 132, the pin retainer 134, the spring 136 and the crimp sleeve 150may be formed of a suitable metal. The epoxy 128 may be a low stressthermal cure epoxy.

The rear housing 140 includes a front section 142 and a rear section144. A pair of opposed latch tabs 142A extend laterally outwardly fromthe front section 142. Ribs 144A are formed on the rear section 144. Apassage 146 extends longitudinally through the rear housing 140 from arear opening 148A to a front opening 148B. According to someembodiments, the passage 146 and the front openings 148A, 148B aregenerally oval or rectangular as shown.

The rear housing 140 is substantially rigid. The rear housing 140 may beformed of any suitable material. According to some embodiments, the rearhousing 140 is formed of thermoplastic. According to some embodiments,the rear housing 140 is formed of a polymeric material such aspolyethermide. According to some embodiments, the rear housing 140 has aflexural modulus of at least about 2 GPa. The rear housing 140 may beformed using any suitable technique, such as molding.

The strain relief boot 160 includes a rear section 161A and a frontsection 161B. A passage 162 extends longitudinally through the strainrelief boot 160 from a rear opening 162A to a front opening 162B. Thepassage 162 has a generally cylindrical rear section 162C and agenerally oval or rectangular front section 162D. Outer ribs 164 areformed on the rear section 161A. Opposed top and bottom retention ribs166 extend inwardly into the passage 162 adjacent the front opening162B.

The strain relief boot 160 may be formed of any suitable material.According to some embodiments, the strain relief boot 160 is formed of apolymeric material. According to some embodiments, the strain reliefboot 160 is formed of thermoplastic, thermoplastic elastomer, orthermoplastic rubber. According to some embodiments, the strain reliefboot 160 has a flexural modulus of between about 0.05 and 0.5 GPa andaccording to some embodiments, the flexural modulus may be higher withsegmented strain relief designed to allow additional flex. The strainrelief boot 160 may be formed using any suitable technique. According tosome embodiments, the strain relief boot 160 is molded.

The fibers 42 extend through the fiber holes 124C in the ferrule 120such that fiber ends 45 are located at the front face 126 of the ferrule120. The fibers 42 are secured in the ferrule 120 by the epoxy 128. Theferrule 120 is positioned in the front housing passage 116 such that aportion of the ferrule 120 extends forwardly of the front housing 110.The rear housing 140 is coupled to the front housing 110 by the tabs142A such that the front section 142 is retained in the passage 116. Theferrule boot 130 and the spring 136 surround the fibers 42. The ferrule120 is held in the passage 116 by the pin retainer 134, which is held inplace by the spring 136, which is braced by the inner housing 140. Thepins 132 extend through the pin holes 124D such that they protrude fromthe front face 126. The pins 132 are also held in place by the pinretainer 134.

The strength yarn bundle 50 and the jacket 60 are secured to the rearhousing 140 by the crimp ring 150. More particularly, segments of theyarn bundle 50 and the jacket 60 are captured between the rear section144 of the rear housing 140 and the crimp sleeve 150, which is crimpedin place.

The strain relief boot 160 is secured to the rear housing 140 by theribs 166, which engage the front edge of the crimp sleeve 150. The rearsection 144 is positioned in the front passage section 162D. A layer oftape 70 or adhesive may be present on the fiber bundle 40 within thefront housing 110 and/or the rear housing 140 and/or a rear portion ofthe ferrule inside the epoxy 128.

As shown in FIGS. 4 and 5, the fiber bundle 40 extends from the frontface 126, through the front housing 110, the ferrule 120, the ferruleboot 130, the spring 136, the rear housing 140, the crimp sleeve 150 andthe strain relief boot 160. The fiber bundle 40 has three segments orsections, as follows: a ribbonized fiber section 40A, a non-ribbonizedfiber section 40B, and a fiber transition section 40C between thesections 40A and 40B. In the ribbonized section 40A, the fibers 42 arealigned in ordered, side-by-side relation with one another (which may bereferred to as a “ribbon configuration”). According to some embodiments,the portions of the fibers 42 in the ribbonized section 40A are disposedand extend generally in a single row or common plane as shown to providea relatively wide, thin construction. In the non-ribbonized section 40B,the fibers 42 are generally loose and disposed in various non-mutualplanes. According to some embodiments, in the non-ribbonized section 40Bthe fibers 42 have a generally round configuration. In the transitionsection 40C, the fibers 42 are undergoing a transition (i.e., changing,converting, transforming or transiting) from the loose configuration tothe ribbonized configuration.

According to some embodiments, the ribbonized section 40A has a lengthL1 (FIG. 4) of at least about 5 mm. According to some embodiments, thelength L1 is between about 5 and 10 mm. According to some embodiments,the transition section 40C has a length L2 (FIG. 4) of between about 20and 30 mm.

With reference to FIGS. 4 and 5, the connector assembly 100 has a fixedor rigid region or portion R1 on the plug side and a strain relief orbendable region or portion R2 on the cable side. In the portion R1, theconnector assembly 100 prevents the segment of the cable 20 therein frombeing bent. According to some embodiments, the rigid portion R1 mayextend rearwardly beyond the rear opening of the housing 105. In theportion R2, the connector assembly 100 may permit non-destructivebending of the cable 20. In particular, in the rear section 161A of thestrain relief boot 160 (i.e., generally the portion having the ribs164), the strain relief boot 160 can be bent with decreasing amounts ofstrain relief and bend radius limitation from the rear housing 140 tothe boot rear opening 162A. The strain relief boot 160 may limit thecable bend angle to a gradual bend to thereby prevent or reduce bendrelated fiber breaks and/or performance losses. Thus, according to someembodiments, at least a portion of the strain relief boot 160 issemi-rigid to provide controlled fiber bend.

Termination of the connector assembly 100 on the cable 20 in accordancewith embodiments of the present invention may be regarded as a round,loose tube fiber cable to array connector direct termination. Theconnector assembly 100 receives a round, loose tube fiber cable sectionand the fiber bundle of the round, loose cable section is converted orreconfigured to a ribbonized fiber bundle within the rigid portion R1 ofthe connector assembly 100. Thus, the entirety of the ribbonized fibersection 40A is contained in the rigid portion R1. Thus, according tosome embodiments, none of the ribbonized fiber bundle is located whereit can be bent in use. This termination allows for the benefits ofround, loose fiber cabling up to the connector termination. For example,as compared to ribbon cable or a cable furcation assembly, a round,loose cable segment may be easier to bend, may be bendable with lessloss of cable performance, and may have less or no preferential bendinglimitations. Moreover, termination in accordance with embodiments of thepresent invention may obviate the need for furcation tubing and therelated expense, mess and effort.

The strain relief boot passage 162 has a rear section 162A that is roundin cross-section (i.e., cylindrical) and properly sized to complementthe round cable 20. In this way, the strain relief boot 160 may properlyengage the directly terminated round cable to provide suitable strainrelief thereto.

According to some embodiments, the connectorized cabling 10 is a cablingor cordage as shown in FIG. 14 including a length of the cable 20 havinga first termination end 20A and a second opposing termination end 20B,and a respective connector assembly 100 installed directly on eithertermination end 20A, 20B of the cable 20. The two connector assemblies100 may be configured the same or differently from one another. Theoptical fibers 42 extend from the termination end 20A to the terminationend 20B. According to some embodiments, the strength yarns 52 arecrimped or otherwise secured directly to both connector assemblies 100as described herein. The strength yarns 52 extend continuously from oneconnector assembly 100 to the other and provide strain relief at bothconnector assemblies. According to some embodiments and as shown, thejacket 60 also extends continuously from and is directly secured to eachconnector assembly 100.

Connectorized cables in accordance with embodiments of the presentinvention such as the connectorized cabling 10 may be formed usingmethods in accordance with embodiments of the present invention.According to some embodiments, the connectorized cable 10 can beassembled as follows.

The strain relief boot 160, the crimp sleeve 150 and the rear housing140 are slid onto the cable 20 and out of the way as shown in FIG. 8(which is a front perspective view). The cable 20 is cut or trimmed suchthat a section of the strength member bundle 50 extends beyond thejacket 60 a length L4, and a section of the fiber bundle 40 extendsbeyond the strength yarn bundle 50 a length L3. According to someembodiments, the length L3 is at least about 45 mm. According to someembodiments, the length L4 is at least about 2 mm.

As also shown in FIG. 8, the jacket 60 is longitudinally cut on opposedlateral sides to form opposed side slits 62 and opposed top and bottomjacket flaps 64. According to some embodiments, the length L5 of theslits 62 is at least about 13 mm. The jacket flaps 64 and end segments54 of the yarns 52 are folded back onto the jacket 60 as shown in FIG. 9and secured in place, for example, using a jacket clamp C1.

The fiber bundle 40 is then ribbonized using any suitable technique.According to some embodiments and with reference to FIG. 9 (which is atop view), the fibers 42 of the fiber bundle 40 are inserted into afiber alignment tool or ribbonizing fixture F1 such that the fibers 42are properly relatively positioned and aligned. The fixture F1 may begrooved or non-grooved. A fiber clamp C2 may be applied to the free ends45 of the fibers 42 to temporarily secure the fiber bundle 40 in theribbonized configuration. Tape 70 (FIG. 10) is applied to the ribbonizedsegment of the fiber bundle 40 to permanently or semi-permanently securethe segment in ribbonized configuration. Alternatively or additionally,a liquid adhesive or the like may be applied to the ribbonized segmentof the fiber bundle 40. Also, other types of fixtures may be employed toassist in ribbonizing the fiber bundle 40. According to someembodiments, a Fujikura FAT-04 tool is used to apply an adhesive to theribbonized fibers. According to some embodiments, the length of the gapbetween the rear edge of the ribbonizing tape 70 (or adhesive) and thebase of the jacket flaps 64 is 15 mm or less.

With reference to FIG. 11 (which is a top view), the end section of thefiber bundle 40 is then stripped to remove the tape 70 or adhesivethereon and the fiber coating layer 44. A thermal heat stripping toolsuch as a Fujiura HJS-02 Hot Jacket Stripper in conjunction with aFujikura FH-12 modified to accommodate the round cable may be used tostrip the fibers 42. In this manner, a bare fiber section 41A is formedextending from the fiber free ends 45 to a taped fiber section 41B. Thebare fiber section 41A likewise has a ribbonized configuration.

With reference to FIG. 12, the spring 136 and the ferrule boot 130 areslid onto the ribbonized fiber bundle 40. The bare fibers of the fibersection 41A are inserted into and through respective ferrule fiber holes124C. The epoxy 128 is injected or otherwise introduced into the ferrulecavity 122 through the top opening 124B and cured to secure the fibers42 in the fiber holes 124C. Portions of the fibers 42 can then becleaved and the front face 126 may be polished as needed. The ferrulepins 132 and the pin retainer 134 are installed on the ferrule 120. Thefront housing 110 is mounted on the ferrule 120. The spring 136 and therear housing 140 are slid forward until the rear housing 140 latcheswith the front housing 110.

With reference to FIG. 13, the jacket flaps 64 and the end sections 54of the strength yarns 52 are folded forward around the rear section 144of the rear housing 140. The crimp sleeve 150 is then slid forward overthe jacket flaps 64, the yarn end sections 54 and the rear housing rearsection 144. The crimp sleeve 150 is then crimped (e.g., using asuitable tool) to secure the jacket flaps 64 and the yarn ends 54 to therear section 144.

The strain relief boot 160 is then slid forward on the cable 20 untilthe retention tabs or ribs 166 engage the front edge of the crimp sleeve150.

According to some embodiments, the foregoing procedure is executed in afactory.

While a single layer ribbonized fiber section is provided in theillustrated embodiments, according to some embodiments, the ribbonizedsection may include multiple, stacked rows of the fibers in side-by-sidealignment.

According to further embodiments of the present invention, methods offorming connectorized cables are provided in which a fiber optic cable20′ is connectorized without the use of any tape (such as tape 70 ofFIG. 10 above) or liquid adhesive. These methods are described belowwith reference to FIGS. 15-17. These methods may be used to attach theconnector assembly 100 described above to the fiber optic cable 20′. Thefiber optic cable 20′ may be identical to the fiber optic cable 20described above, except that it does not include either the tape 70 orany liquid adhesive.

Referring to FIG. 15, operations may begin by sliding the strain reliefboot 160, the crimp sleeve 150, the rear housing 140 and the spring 136onto the cable 20′ and out of the way. The cable 20′ may then be cutsuch that a section of the fiber bundle 40 extends beyond the both thestrength yarn bundle 50 and the jacket 60. The jacket 60 islongitudinally cut on opposed lateral sides to form opposed side slits62 and opposed top and bottom jacket flaps 64. The jacket flaps 64 andend segments of the strength yarn bundle 50 are then folded back ontothe jacket 60 and may secured in place, for example, using a jacketclamp (not shown). In some embodiments of these methods, the use of thisjacket clamp may not be necessary.

As shown in FIG. 16, the fiber bundle 40 is then ribbonized using afiber alignment tool 200 such that the fibers 42 are properly positionedand aligned. In some embodiments, the fiber alignment tool 200 mayinclude a base 210 and a cap 230. The base 210 may include a groove 220that receives the fibers 42. In some embodiments, a single groove 220may be provided, while in other embodiments, individual grooves (notshown) may be provided for each of the fibers 42. In still otherembodiments, the groove 220 may be omitted, and other means (e.g.,posts) may be used to facilitate properly positioning and aligning thefibers 42. In some embodiments, the cap 230 may comprise a hinged cap.Additionally, magnets (not shown) may be included in either the base 210or the cap 230. These magnets may be used to hold the cap 230 in placeon the base 210 once the fibers 42 have been inserted into the base 210and properly positioned and aligned. The cap 230 holds the fibers 42 intheir proper position and alignment within the base 210 with sufficientforce such that the fibers 42 do not move relative to each other duringnormal handling, fiber coating stripping and connector assembly. Asdescribed below, the fiber alignment tool 200 may be removed once epoxy128 is inserted into the ferrule boot 130 and cured.

As shown in FIG. 16, the base 210 of the fiber alignment tool 200 ispositioned under the exposed fibers 42 and under the end portion of thejacket 60 (in some embodiments the fiber alignment tool 200 need not bepositioned under the jacket 60). The fibers 42 are then positioned, forexample, in the groove 220 in the base 210 of the fiber alignment tool200. The fibers 42 transition into a ribbonized configuration in thefiber alignment tool 200, and are positioned in the proper order, buthave a loose configuration behind the fiber alignment tool 200. Next,the cap 230 is closed onto the base 210 such the fiber alignment tool200 holds the ends of the fibers 42 in the ribbonized configuration.

Next, a thermal heat stripping tool (or other appropriate device) isused to strip the fiber coating layer 44 from the end sections of thefibers 42 that extend beyond the fiber alignment tool 200. In thismanner, a bare fiber section 41A is formed that has a ribbonizedconfiguration. In other embodiments, the ferrule boot 130 may be slidonto the fibers 42 (in the manner discussed below) before this strippingoperation is performed.

With reference to FIGS. 16 and 17, epoxy 128 is injected or otherwiseintroduced into the cavity 122 of ferrule 120 through the top opening124B. A vacuum may be used to draw the epoxy 128 through the ferrule120. The bare fiber section 41A of the ribbonized fiber bundle 40 isthen slid through the epoxy 128 and into the ferrule fiber hole 124C(this is done while the fiber alignment tool 200 remains in place). Theferrule boot 130 is then pushed into the rear opening 124A in theferrule 120. Next, the epoxy 128 is cured to secure the fibers 42 in thefiber hole 124C. Once the epoxy 128 has been cured, the fiber alignmenttool 200 may be removed. Portions of the fibers 42 can then be cleavedand the front face 126 of ferrule 120 may be polished as needed. Theferrule pins 132 and the pin retainer 134 may then be installed on theferrule 120, and the front housing 110 may be mounted on the ferrule 120(see FIGS. 2-3). The spring 136 and the rear housing 140 are slidforward until the rear housing 140 latches with the front housing 110.Finally, the connectorized cable assembly may be completed by performingthe crimping operations discussed above with respect to FIG. 13. In someembodiments, the spring 136 may alternatively be placed over the fibers42 in front of the split portion of the jacket 60 instead of beingplaced onto the cable 20′ in the manner discussed above with referenceto FIG. 15. In such embodiments, the alignment tool 200 may include acutout portion (not shown) that receives the spring 136 during assemblyof the ferrule 120.

Pursuant to the above-described termination method, the fiber alignmenttool 200 may be used to hold the fibers 42 in proper alignment untilafter the epoxy 128, the bare fiber section 41A and the ferrule boot 130are inserted into the ferrule 120 and the epoxy 128 cured, therebyallowing the operation of adding a tape 70 or liquid adhesive to theexposed fibers 42 to be omitted. Here, the fibers 42 are in ribbonizedconfiguration within the ferrule boot 130, but have a loose fiberconfiguration immediately behind the ferrule boot 130.

It will be appreciated that other configurations of connector assembliesmay be employed. For example, the ferrule pins 132 may be omitted toform a female connector assembly for use with the male connectorassembly 100 as illustrated. The pins 132 of the male connector assembly100 may be received in the pin holes of the female connector assembly tofacilitate alignment between the respective mating fiber ends. The maleand female connector assemblies may be held together by an adapter, forexample.

The foregoing is illustrative of the present invention and is not to beconstrued as limiting thereof. Although a few exemplary embodiments ofthis invention have been described, those skilled in the art willreadily appreciate that many modifications are possible in the exemplaryembodiments without materially departing from the novel teachings andadvantages of this invention. Accordingly, all such modifications areintended to be included within the scope of this invention. Therefore,it is to be understood that the foregoing is illustrative of the presentinvention and is not to be construed as limited to the specificembodiments disclosed, and that modifications to the disclosedembodiments, as well as other embodiments, are intended to be includedwithin the scope of the invention.

That which is claimed is:
 1. A method for forming a connectorized fiberoptic cabling assembly, the method comprising: providing a loose tubefiber optic cable that includes an optical fiber bundle that has aplurality of optical fibers having a loose, non-ribbonizedconfiguration, at least one strength member and a jacket surrounding theoptical fiber bundle and the at least one strength member, wherein anend section of the optical fiber bundle extends beyond the strengthmember and the jacket; receiving a portion of each optical fiber in afiber alignment tool to align end portions of the optical fibers in aribbonized configuration; stripping a coating layer from the end of eachof the optical fibers while the optical fibers are received in the fiberalignment tool; inserting the ends of the optical fibers that arealigned in the ribbonized configuration within a fiber passage of aferrule while the optical fibers are received in the fiber alignmenttool; and then removing the fiber alignment tool from the plurality ofoptical fibers.
 2. The method of claim 1, wherein the ends of theoptical fibers are inserted into the fiber passage of the ferrule afterthe coating layer is stripped from the end section of each of theoptical fibers.
 3. The method of claim 1, wherein stripping the acoating layer from the end of each of the optical fibers comprises usinga thermal heat stripping tool to strip an environmental protection layerfrom the end of each optical fiber.
 4. The method of claim 1, furthercomprising: introducing an epoxy into the ferrule; curing the epoxy tosecure the optical fibers in the ribbonized configuration within theferrule.
 5. The method of claim 4, wherein the fiber alignment tool isremoved from the optical fibers after the epoxy is cured.
 6. The methodof claim 4, wherein a vacuum is used to draw the epoxy into the ferrule.7. The method of claim 4, wherein the epoxy is introduced into theferrule before the ends of the optical fibers are inserted into thefiber passage of the ferrule.
 8. The method of claim 1, whereinreceiving a portion of each optical fibers in the fiber alignment toolto align end portions of the optical fibers in the ribbonizedconfiguration comprises: opening a cap of the fiber alignment tool;receiving the portions of the respective optical fibers in a base of thefiber alignment tool; aligning the end portions of the optical fibers inthe ribbonized configuration within the fiber alignment tool; andclosing the cap of the fiber alignment tool onto the base of the fiberalignment tool to hold the end portions of the optical fibers in theribbonized configuration.
 9. The method of claim 8, wherein the base ofthe fiber alignment tool includes at least one groove.
 10. The method ofclaim 8, wherein at least one of the base and the cap of the fiberalignment tool includes magnets, and wherein the magnets hold the cap inplace on the base.
 11. The method of claim 1, further comprising:sliding a strain relief boot and a rear housing of a connector housingonto the loose tube fiber optic cable prior to receiving the portions ofthe respective optical fibers in the fiber alignment tool; andconnecting a front housing of the connector housing to the rear housingof the connector housing.
 12. The method of claim 11, further comprisingsecuring at least one of the jacket and the strength member to theconnector housing.
 13. The method of claim 1, wherein the connectorizedfiber optic assembly includes the loose tube fiber optic cable and aconnector housing that is mounted on an end of the fiber optic cable,wherein the connector housing includes: a substantially rigid fronthousing; a substantially rigid rear housing; and a strain relief boot.14. The method of claim 1, further comprising sliding a ferrule bootonto the optical fibers before the ends of the optical fibers that arealigned in the ribbonized configuration are inserted within the fiberpassage of the ferrule.
 15. The method of claim 14, wherein the ferruleboot is slid onto the optical fibers before the coating layer isstripped from the end of each of the optical fibers.
 16. The method ofclaim 14, wherein the ferrule boot is slid onto the optical fibers afterthe coating layer is stripped from the end of each of the opticalfibers.